Within the singularity, matter is infinitely compressed into a region of infinite density.

If neutron degeneracy is not enough to resist the star's collapse it will continue to shrink until the matter is all compressed into an infinitely small, infinitely dense point called a singularity.

Penrose introduced the scope of modern physics and followed with a description of possible models of the universe based on criteria from the theory of relativity, including the effect of singularities.